I'm confused about physical and logical topology. I've read online and know their definitions, but still

Question

I still don't get it. People define the two terms, but they don't explain it throughly.

I've seen the way machines are connected so that they form a bus, ring, star, mesh.

So, I was thinking these 4 topologies are always "physical" b/c physical topology concerns with the way machines are connected.

But, then again, I've read that there're also logical Bus and logical Ring. Does this mean the 4 topologies can be both "physical" and "logical"?

Answer 1

Yes, the four topologies can be simulated which means they CAN be logical. A practical example of having a logical network over a different physical network is VLANs.

http://en.wikipedia.org/wiki/Virtual_LAN

You can look into this, it might clear some confusions like why logical when physical ? etc. etc.

Answer 2

Physical topology refers to how machines are physically interconnected

The logical topology is how the data travels is configured to travel through this network.

There are several practical reasons why these 2 may differ.
For example you can for simplicities sake use a physical Star topology, but logically use a Token Ring topology where each machine waits for the token to transmit in this ring topology.

Answer 3

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